This invention relates to differential gearings.
Conventional differential gearings are composed of a rotary input shaft having a main drive rotating member, a plurality of intermediate rotating members for transmitting sequentially rotatory power of the main drive rotating member with revolving around or staying on the axis of the input shaft, and a rotary output shaft having a driven rotating member to which rotatory power of the final intermediate rotating member is transmitted.
The above-mentioned conventional differential gears, however, have problems such that although they are constructed to change the speed of rotation of the output shaft from that of the input shaft, they are lack in stability of torque (rotatory power) of the output shaft, and in particular a decrease in speed of rotation of the output shaft causes a decrease in torque, thereby exhibiting insufficient function as power transmission.
This invention was done to solve the conventional problems mentioned above, and is intended for providing a differential gear capable of outputting a sufficient torque in a strong and stable manner even though the speed of rotation of the output shaft is decreased in comparison with that of the input shaft.
The differential gearing in accordance with the present invention comprises a rotary input shaft having a main drive rotating member, a plurality of intermediate rotating members for transmitting sequentially rotatory power of the main drive rotating member with revolving around or staying on the axis of the input shaft, and a rotary output shaft having a driven rotating member to which the rotatory power of the final intermediate rotating member is transmitted, wherein number of revolutions of the intermediate rotating members around the axis is adapted to increase with a decrease in speed of rotation of the output shaft in comparison with the speed of rotation of the input shaft, and wherein at least a part or all of the intermediate rotating members have inertial force caused by the rotation, or a rotating or non-rotating inertial body revolvable and/or rotatable with the intermediate rotating members, such as flywheel or weight is provided. Furthermore, the differential gearing is characterized in that each of said rotating members is gear or friction gear. The differential gearing of the invention is characterized in that mass or shape of said inertial body or its distance from the revolvable shaft or rotatable shaft is varied alone or in combination.